Analog-to-digital converters (ADCs) convert analog signals into digital signals by sampling the analog signal onto capacitors and quantizing the samples. In an example, an N-bit quantizer provides 2N−1 decision levels over its full scale range, where each decision level corresponds to one distinct digital output code. The sampled analog signal is quantized to determine a digital code that is closest to the analog sample. The difference between digital code and the analog sample represents a quantization error.